Photochromic Conjugated Microporous Polymer Manifesting Bio-Inspired pcFRET and Logic Gate Functioning

Abstract

Design and synthesis of solid-state photochromic materials remain a challenge because of high structural constrain. However, this can be mitigated in attaining structural flexibility by introducing permanent porosity into the system. Here, we report for the first time the design and synthesis of a photochromic conjugated microporous polymer (pcCMP) by assembling photochromic dithienylethene aldehyde and benzene-1,3,5-tricarbohydrazide. The yellow photo-isomer pcCMP-O gets converted to a deep-green photo-isomer pcCMP-C by UV-light irradiation, which can be reverted to pcCMP-O by visible light or thermal treatment. Owing to the thermo-irreversible nature, the pcCMP is found to be suitable for designing an INH functioning logic gate. pcCMP-C shows highly enhanced conductivity (92 times) because of enhanced conjugation compared to pcCMP-O. Furthermore, we demonstrate the bio-inspired photo-switchable pcFRET process by encapsulation of a red-emissive green fluorescent protein (gfp) chromophore analogue into the pcCMP. This material shows high processibility and has been exploited further for secret writing.